The stands of tectorum () in the Caribbean lowlands of : a managed pioneer palm facing river dynamics

Claudia Torres*, Gloria Galeano & Rodrigo Bernal Instituto de Ciencias Naturales, Universidad Nacional de Colombia, Apartado 7495, Bogotá, Colombia; [email protected], [email protected], [email protected] * Correspondence

Received 12-vi-2014. Corrected 10-XII-2014. Accepted 19-I-2015.

Abstract: is a palm that grows in large populations on seasonally flooded savannas in the Caribbean region of Colombia, where its stems and expanded are used in construction, and its unexpand- ed leaves are used to make handicrafts. We studied abundance and population structure in 34 plots of 20×10m (0.68 ha) of three localities (Plato, Córdoba and Magangué) at the Mompox Depression, an inner delta formed by the confluence of four large rivers. We recorded growth and mortality of 164 palms of different size classes over 13 months, and additionally we estimated seedling and juvenile mortality in two 10x10m plots within the same sites. Data analysis using Kolgomorov-Smirnov (KS), Kruskal-Wallis and Mann-Whitney tests were made on Statgraphics Plus and SPSS. We related the structure and dynamics of the palm stands to flood intensity. Copernicia tectorum has the fastest production rate recorded for any palm (19-23 leaves/year in subadults and adults), and a short life span of ca. 46 years. The abundance, density and high leaf production rate of this palm offer a great potential for the sustainable use of its unexpanded leaves (especially at Plato, where there are ca. 480ha of palm stands with 300-1 000 individuals/ha), as leaf harvest from subadult and adult individuals does not appear to affect population structure. The palm is a pioneer of the flood plain, and the palm stands at particular sites appear to wax and wane following sedimentation dynamics, in which the species plays in impor- tant role. Current population structure and the scarce recruitment of juveniles at the study site suggest that the population is waning in that site. Management actions should be taken to reestablish natural river dynamics at the lagoon complex where the palm grows. Appropriate management of palm stands may contribute to minimize any negative effects of river dynamics. Rev. Biol. Trop. 63 (2): 525-536. Epub 2015 June 01.

Key words: leaf harvest impact, leaf production, Mompox Depression, NTFP, pioneer , population struc- ture, seasonally flooded savanna.

Fibers obtained from wild palms play a in Northern Colombia, this species is the domi- significant role in Colombian handicraft pro- nant element in the vegetation. In these areas duction (Linares, Galeano, García, & Figueroa, the palm has a major ecological role, due both 2008). One of the most important fiber-pro- to its abundance and to the numerous interac- ducing palms in the Caribbean lowlands is the tions with other organisms-it harbors termites, sará palm, Copernicia tectorum (Kunth) Mart., wasps, ants, birds, and epiphytes, and its fruits which grows only in dry savannas in Northern are food for fish, birds, and mammals (Troth, Colombia and Venezuela, where it forms exten- 1987; Torres, 2013; pers. obs.). sive stands in areas that are subject to severe The sará palm also has a great importance drought during the dry season, and to perma- to local communities, as its leaves and stems are nent flooding during the rainy season (Troth, used in construction, and fiber obtained from 1987; Galeano, & Bernal, 2010). In some its unexpanded leaves is the base of a flourish- lagoon complexes at the Mompox Depression, ing handicraft activity of local importance. In

Rev. Biol. Trop. (Int. J. Trop. Biol. ISSN-0034-7744) Vol. 63 (2): 525-536, June 2015 525 the municipalities of Magangué (department regimes at three localities in the Mompox of Bolívar) and Plato (department of Magda- Depression, in the Caribbean region of Colom- lena), along the Magdalena river, at least 200 bia. We also present data on the impact of river families are involved in this handicraft produc- floods on the populations, and describe a plau- tion (Linares et al., 2008). However, the ongoing sible scenario of changes in the palm stands in process of deforestation and lagoon desiccation the long run. for establishing crops and for cattle ranching has reduced the palm populations, causing a MATERIALS AND METHODS decrease of fiber availability and a greater pres- sure on the surviving palm stands (Linares et Study site: We studied populations of C. al., 2008; Torres, 2013). Sustainable manage- tectorum around Ciénaga Zárate, and Ciénaga ment of this species requires an understanding Cascaloa, a complex of lagoons in the flood- of the stands, their role in these savannas and lands of the lower Magdalena river, near the lagoon complexes, and the possible impact of towns of Plato and Magangué, in the depart- leaf harvest on populations. ments of Magdalena and Bolívar, in Northern Extraction of non-timber forest products Colombia. This area is part of the Mompox (NTFPs) has been the subject of a long debate Depression (Depresión Momposina), Colom- as to the scope and extent of the research that bia’s largest wetland area, considered as an is required to guarantee sustainability (Peters, inner delta formed by the confluence of four 1996; Wong, Thornber, & Baker, 2001; Tick- large rivers -Magdalena, Cauca, Cesar, and tin, 2004). There seems to be a consensus, San Jorge (Plazas, Falchetti, Van der Hammen, however, about the need of basic biological & Botero, 1988). This area is classified as trop- and ecological studies, as a starting point to ical dry forest in Holdridge’s life zone system plan sustainable management, even for those (Instituto Geográfico Agustín Codazzi, 1977), species that have been traditionally used. The with an average temperature of 28°C, and required basic information includes abundance, 1 250-1 500mm annual rainfall. Intense rains density, population structure, production rate fall during March-May and August-December, of the organ used, and the plant’s over- and there are severe droughts during June- all growth rate (Peters, 1996), as well as an July and December-February. Flood dynamics assessment of any other ecosystem services throughout the seasons determines a water flow involving the used species, and its role in the from the Magdalena river to the lagoons and ecosystem. A first sign of unsustainable harvest vice versa. Floods follow the rainfall regime of is evidenced in size class distribution (Peters, the river basin’s midlands and highlands, which 1996; Bernal, & Galeano, 2013). Although is mostly bimodal, with a peak from mid-April for many plants the ideal size class distribu- to early June, and a second, higher one, from tion has an inverted-J shape (many seedlings mid-August to December. As a result, there and a decreasing number of juveniles and is a first flood between May and July and a adults), other size class distribution curves are second one between October and December. found among species growing in open areas or However, flood frequency, duration and level among those subject to extreme environmental have changed in recent years, as a result of changes (Peters, 1996). Because of this, an road construction, lagoon dessication, and the assessment of harvest impact must be based illegal use of lagoons and shores (Ministerio on the study of both harvested and unharvested del Medio Ambiente [MMA], 2002). This is populations (Bernal, & Galeano, 2013). evidenced by the fact that the hydrological In this paper we used data on abundance, station at Plato recorded for the Magdalena density, and size class distribution and plant river in February 2010 a lower level of 4.2m, growth, to assess the state of populations of close to the lowest value ever recorded (4.0m Copernicia tectorum under various harvest in 1977), and well below the average for that

526 Rev. Biol. Trop. (Int. J. Trop. Biol. ISSN-0034-7744) Vol. 63 (2): 525-536, June 2015 month (6.5m); similarly, in December 2010 there was a maximun level of 12.8m, well over the average for that month (9m) (Instituto de High 1.7** 1, 5-7 Cascajal 9°19’05” Hidrología, Meteorología y Estudios Ambien- 74°48’37 tales de Colombia, 2011).

Study species: Copernicia tectorum is a 2-4

solitary palm with an erect stem 5-10m tall, 2.2** Pascuala 9°25’13” Magangué 74°50’11”

20-30cm in diameter, which remains cov- Intermediate ered for some time with persistent leaf bases (Galeano, & Bernal, 2010). It has a mass of

adventitious roots at the base, which have been – 12 High Several considered as an adaptation to whithstand the 1.0-1.5* 9°23’18” 74°50’7” long floods (Throth 1987). The crown has 15-25 palmate, circular leaves composed of numerous rigid segments up to 1 m long, with up to 1.6 3 m long petioles that bear hooked spines along – 1.3-1.5* Córdoba 9°26’15” 74°49’43”

their margins. Inflorescences are interfoliar and Tacamocho Intermediate project beyond the leaves. They have numerous branches and bear small, hermaphrodite flow- ers. Fruits are ovoid to obovoid, ca. 3cm long, 3 – bright black when ripe, and have one seed. In 9°40’ 74°45’12” 3.95-4.51** Colombia this species grows only in the Carib- Unharvested bean lowlands (Galeano, & Bernal, 2010). It is cuchillo Ciénaga

unusual in its adaptation to extreme conditions able 1 T 2 of flooding and drought and its resistance to – Low Silencio fire (Troth, 1987) (Fig. 1). 9°42’15” 3*/3.94** 74°45’25”

Sampling: Data were taken at three locali- ties: Plato (Magdalena) and Magangué and 5 –

Córdoba (Bolívar). These are the areas where Low Plato 3.63** Plazoleta 9°41’53” harvest is most intensive and handicraft pro- 74°46’24” duction takes place. The three sampling locali- ties differed in the nature of the palm stands, in the level of flooding, and in harvest intensity 4 – Low

(Table 1). We chose sites with a history of use 4.27** 9°42’43” 74°47’32” of at least 20 years, in order to be able to detect Macho-solo the effect of harvest on the palm populations. lowlands of Colombia tectorum at the Caribbean of the sites sampled for Copernicia Characteristics Sites were identified with the help of land owners and harvesters. Five sites were chosen 5 1-7 Low 4.03** Cardonal 9°43’36”

at Plato, where the largest palm populations 74°47’37” occur (area >1ha), mostly on common lands. Four of these sites are harvested (Cardonal, Machosolo, Plazoleta, and Silencio); at the fifth site (Ciénaga Cuchillo) there was no records of Site

spear leaf harvest, although expanded leaves Locality were occasionally harvested for thatching. At Harvest intensity Flood level (m) Flood level Number of plots Size classes Coordinates N W Magangué and Córdoba, palm stands are small * Period: November 2009-January 2010 / ** October 2010-January 2011.

Rev. Biol. Trop. (Int. J. Trop. Biol. ISSN-0034-7744) Vol. 63 (2): 525-536, June 2015 527 Fig. 1. Palm stands of Copernicia tectorum at Plato, Magdalena, at the Caribbean lowlands of Colombia. (A) During drought, (B) During flood.

(<1ha), scattered, and they are all found on 34 plots of 20×10m, 19 of them in Plato, 12 in private property. Flood level at all sites was Magangué and three in Córdoba. Plot number measured on basis of the marks left by water on was proportional to the area of the palm stands. the palm stems or on neighboring . At each plot we counted and tagged all individ- Field work was carried out in February- uals, and recorded the following variables for March 2010 and April 2011. We established each individual of C. tectorum: stem height (up

528 Rev. Biol. Trop. (Int. J. Trop. Biol. ISSN-0034-7744) Vol. 63 (2): 525-536, June 2015 to the petiole base of the oldest live leaf); diam- For data analysis, we divided the popula- eter at breast height (1.3m) of naked stems; tion into seven size classes, based on devel- number of leaves; and number and develop- opmental traits, like leaf division, occurrence mental stage of reproductive structures. Addi- of an aerial stem, and reproduction (Table 2) tionally, for juveniles lacking an aerial stem we (Galeano et al., 2010). When plotting segment recorded the length and number of segments of number vs. segment length, we found a change the youngest expanded leaf; for seedlings we in the slope of the curve at 20 segments (data recorded lamina length and number of primary not shown); because of this, we took >20 seg- veins of the youngest expanded leaf (Galeano ments as the lower limit of the juvenile 2 class. et al., 2010). We studied leaf production by The presence of an aerial stem marks the divi- marking with colored wire the youngest leaf sion of juveniles 2 and juveniles 3, but some of 164 palms of different size classes at three stemmed palms have leaves similar to those sites in Plato and Magangué (Table 1). Thirteen of juvenile 2; because of this, we chose as months later we counted new leaves produced, the upper limit of the juvenile 2 size class the and the increase in number of primary veins average number between the highest number or segments from one leaf to the next one in of segments of a stemless palm and the lowest 87 palms that survived. We used the mortality number of segments of a stemmed palm. We rate of these marked palms to complement data then used that figure to classify any particular obtained from two 10x10 plots, one at Plato individual as either juvenile 2 or juvenile 3. We and one at Magangué. chose a height of 1.6m as the upper limit of Abundance was estimated using Google the juvenile 3 category, as this was the lowest Earth images and aerial photographs of the height recorded for a reproducing individual. Instituto Geográfico Agustín Codazzi (flight As palms age, they shed the persistent leaves IGAC 2719 of 2004), in which palm crowns from the base. Based on this, we defined the of adults and subadults can be recognized. The limit of adults 1 and adults 2 at 4.8m, the aver- area of the palm stands at Plato was calculated age height of the stem’s naked portion. on the images, and abundance was estimated Duration of the seedling and juvenile1 and through a direct count of crowns on the images, juvenile 2 age classes was estimated by divid- combined with plot data. This estimate did ing the range in number of veins (seedlings) or not include isolated palms or areas smaller of leaf segments (juveniles) by the annual rate than 1ha, nor did it include the palm stands of of increase in veins or segments, respectively. Magangué and Córdoba, where the smaller size For juveniles 3, subadults, and adults, we com- of the stands and of the palms did not make bined stem length, internode length, and leaf them clearly recognizable on the images. production rate. Leaf scars are close to each

TABLE 2 Parameters and values used for defining size classes of Copernicia tectorum at the Caribbean lowlands of Colombia

Number of Stem height Reproductive Size class Leaf shape Aerial stem segments (m) structures Seedling Simple, lanceolate N/A Absent N/A Absent Juvenile 1 Segmented ≤20 Absent N/A Absent Juvenile 2 Segmented >20 Absent N/A Absent Juvenile 3 Segmented >20 Present ≤1.6 Absent Subadult Segmented >20 Present >1.6≤3.0 Absent Adult 1 Segmented >20 Present (usually with persistent leaves >3.0≤4.8 Present from the base) Adult 2 Segmented >20 Present (usually without persistent >4.8 Present leaves from the base)

Rev. Biol. Trop. (Int. J. Trop. Biol. ISSN-0034-7744) Vol. 63 (2): 525-536, June 2015 529 other (Fig. 2), and most stems have damages at several places, thus measuring the length of individual internodes throughout the stem is not feasible on all individuals; therefore, we obtained average internode length by dividing the length of a stem portion 0.5-1m long by the number of scars in that portion in stems where scars could be clearly identified. Measurements were taken in a sample of ten individuals of various sizes and at different sites. The total age of a stemmed individual was calculated as the total number of internodes estimated for its size, divided by the leaf production rate for the corresponding size, and adding the estimated age for the stemless phase (Corner, 1966; Pinard, & Putz, 1992; Galeano et al., 2010). As leaf production rate did not differ between Magangué and Plato, data were there- fore pooled. Similarly, leaf production rates of adults 1 and adults 2 were also pooled, as the sample of adults 2 (four palms) was too small. Fig. 2. Stems of Copernicia tectorum at Plato, Magdalena, at the Caribbean lowlands of Colombia. The arrows We compared population structure among indicate three successive leaf scars. the three localities Magangué, Córdoba and Plato and among sites at Plato using Kolgo- morov-Smirnov (KS) test (Sokal, & Rohlf, The population at Magangué differed from 1995). Palm density and leaf production rate those at Plato and Córdoba in seedlings, juve- were analyzed with the non-parametric Krus- niles 3, and adults 1; it also differed from kal-Wallis test. When significant differences populations at Plato in terms of adults 2. Plato were found, we used the Mann-Whitney test to and Córdoba differed only in adults 2 (Fig. 3). explore which groups were different. All analy- At Magangué most palms (88%) were juve- ses were made in Statgraphics Plus and SPSS. niles 3, whereas reproductive individuals (1%) and seedlings (4%) were scarce (Fig. 4A). At RESULTS Plato and Córdoba there were high proportions of seedlings (65% and 66%, respectively), a The area of palm stands at Plato was esti- decreasing amount of juveniles 1 (8% and 29%, mated at 480 ha, located between the Magda- respectively), but few juveniles 2, juveniles 3, lena river and the Zárate lagoon. The number and subadults (5.7% and 1.3%, respectively, of adults and subadults was estimated as ca. when pooled). Plato, in turn, had a remarkable 273 000. Overall stand density ranged between proportion of adults 2 (16%) (Fig. 4B), while 9 and 391 individuals per plot, i.e., 450-19 550 this class was scarcely represented in Córdoba individuals per ha. Adult density was 300-1 000 (1%) and did not occur in Magangué. individuals per ha at Plato, 0-100 individuals Sites within Plato, including the unhar- per ha at Magangué, and 250-950 individu- vested one, did not differ among them, except als per ha at Córdoba. In general, density was for a difference in adults 2 between Silencio significantly different at the three localities y Machosolo. Only the sites Plazoleta, Car- (KV=15.3748, p=0.0005), but not within the donal and Silencio had individuals in all size sites at Plato, including the unharvested site classes. The unharvested population at Cié- (KV=5.4476, p=0.2444) (Table 3). naga Cuchillo lacked juveniles 2, juveniles 3,

530 Rev. Biol. Trop. (Int. J. Trop. Biol. ISSN-0034-7744) Vol. 63 (2): 525-536, June 2015 TABLE 3 Average density of individuals of Copernicia tectorum in plots of 0.02ha from the Caribbean lowlands of Colombia

Locality Sites within Plato Size class Ciénaga cuchillo Magangué Córdoba Plato* Plazoleta Silencio Cardonal Machosolo (unharvested) Seedling 0.8 200.3 39.1 11 3.5 70.2 75.8 35.0 Juvenile 1 0.5 89.7 4.8 0.8 6.5 10.6 5.0 1.3 Juvenile 2 0.6 0.0 2.0 0.8 4.5 4.2 0.3 0.0 Juvenile 3 17.2 2.0 0.5 0.4 0.5 1.8 0.0 0.0 Subadult 0.4 2.0 1.0 0.8 1.0 2.0 1.0 0.0 Adult 1 0.2 7.3 3.2 2.2 2.5 6.2 3.0 2.3 Adult 2 0.0 2.7 9.7 11.2 14.5 7.0 6.8 9.0 Total 19.6 304.0 60.3 27.2 33.0 102.0 91.8 47.7

* Data from Plato are the average of the five sampled sites, including the unharvested one.

100 Size class 90 Seedling Juvenile 1 80 Juvenile 2

70 Juvenile 3 Subadult 60 Adult 1 Adult 2 50

% of individuals 40

30

20

10

0 Magangué Córdoba Plato Localities

Fig. 3. Population structure of Copernicia tectorum at localities of Magangué, Córdoba and Plato, at the Caribbean lowlands of Colombia. and subadults, and it had scarce juveniles 1 correlation between initial leaf number and leaf (3%) (Fig. 5). production rate either at Plato or Magangué There was a steady increase in leaf pro- (r=0.459 at Plato and 0.099 at Magangué). duction rate with age, reaching a maximum Palms start to reproduce when they are ca. 23.9 of 23.4 leaves per year in subadults, and then years old; the age of the tallest palm measured decreasing to 19 leaves per year in adults (7.4m) was estimated as 46 years. Mortality (Table 4). It took adult palms about one year to at Plato was highest for seedlings (57%), and replace their whole crown. There was no strong decreased steadily for juveniles (juveniles 1:

Rev. Biol. Trop. (Int. J. Trop. Biol. ISSN-0034-7744) Vol. 63 (2): 525-536, June 2015 531 Fig. 4. Typical structure of the Copernicia tectorum palm stands at the Caribbean lowlands of Colombia. (A) At Magangué (Bolívar), where juveniles 3 dominate (average height, 1m), (B) at Plato (Magdalena), where seedlings and adults 2 dominate.

43%; juveniles 2: 40%; juveniles 3: 35%). Mortality in Magangué was 2.3% for juveniles 2 and 3.35% for juveniles 3. adults, with a frequency that allows the palms DISCUSSION to recover (Torres, 2013; Torres et al., in prep.). At Magangué, on the other hand, juveniles 3 The similar demographic structure of C. predominate and there are scarce seedlings and tectorum at Plato and Córdoba, both at har- adults. This appears to be a result of leaf har- vested and unharvested sites (biased towards vest, as the scarcity of adults forces harvesters old individuals, with abundant seedlings and to cut spear leaves from individuals as young scarce recruitment into the juvenile 1 and juve- as juveniles 3, which delays their growth and nile 2 classes), suggests that spear leaf harvest renders them stunted. is not affecting the populations. This is prob- Leaf production rate (19-23 leaves/yr in ably due to the fact that at this site leaves are subadults and adults) appears to be the fast- harvested only from size class subadults and est one recorded so far for any palm (cf.

TABLE 4 Growth, size class duration and accumulated age for the size classes of Copernicia tectorum at the Caribbean lowlands of Colombia

Annual increase in Increase leaf Annual leaf Class Accumulated Size class Size class limits veins or segments scars * production rate duration (yr) age (yr) Seedling 3-8 veins 3.14 (±2.13) 4.8 1.59 0-1.59 Juvenile 1 9-20 segments 2.95 (±2.21) 6.6 4.07 1.59-5.66 Juvenile 2 21-34 segments 2.96 (±2.45) 11.46 4.73 5.66-10.39 Juvenile 3 Stem≤1.60m 151 19.31 7.82 10.39-18.21 Subadult Stem>1.6≤3.0m 132 23.38 5.65 18.21-23.86 Adult 1 Stem>3.0≤4.8 m 169 18.99 8.90 23.86-32.76 Adult 2 Stem>4.8≤7.4m 245 18.99 12.90 32.76-45.66

* Average internode length: 1.06cm.

532 Rev. Biol. Trop. (Int. J. Trop. Biol. ISSN-0034-7744) Vol. 63 (2): 525-536, June 2015 Fig. 5. Unharvested stands of Copernicia tectorum at Ciénaga Cuchillo, in the Caribbean lowlands of Colombia. Note the dominance of adults 1 (average height, 4.2m).

Henderson, 2002; Bernal & Galeano, 2013), death; after the long drought of early 2010, comparable only to that of Hyphaene petersiana at all of our study sites we found palms with (Fanshawe, 1967), another coryphoid palm that all their leaves burned but still producing a grows in similar environments in Africa. Such new spear leaf. a fast leaf production rate accounts for the fast Population structure at Plato and Córdoba growth and the short life span. Leaf production resembles Peters’s (1996) type III size class does not seem to be affected by flood level, as distribution, with most individuals of the same there were no differences between Plato and age or size, which is common in heliophitic Magangué, although they had different flood and pioneer plants. Several traits in the life levels (4m and 1.7-2.2m respectively). history of C. tectorum indicate that it is indeed An apparent cause of death in juveniles a pioneer of riverine floodlands, as suggested was the accumulation on their crown of plants by Troth (1987) for the populations of the brought by the flood, which got trapped by the Venezuelan savannas. Not only does it thrive petiole thorns, sometimes completely covering in open areas, where it forms dense, mono- the crown; additionally, hemiepiphytes often dominant stands, as other riverine pioneers do grew among the leaf bases, probably from (cf. Parolin, Oliveira, Piedade, Wittmann, & seeds brought also by the flood. This situation Junk 2002), but it also has a short establishment did not appear to affect plants over 3m tall, phase of only 10.4 years, and its life span (46 whose crown emerged above the flood level, or years) is one of the shortest recorded for any older palms with naked stems. iteroparous palm (Henderson, 2002). Fires taking place during the dry sea- As with other pioneer riverine plants, flood son did not appear to be a relevant cause of dynamics appears to be the most important

Rev. Biol. Trop. (Int. J. Trop. Biol. ISSN-0034-7744) Vol. 63 (2): 525-536, June 2015 533 factor influencing the populations of C. tec- is probably altered when the palm stands are torum. First, flood water is known to be the destroyed for clearing the land or for using the primary dispersal agent of C. tectorum (Troth, stems, or when their structure is altered through 1987). Additionally, flooding probably increas- overharvest, and herbaceous and shrubby veg- es seedling recruitment, as water soaking favors etation with thinner stems and smaller leaves, seed germination, as shown by Kitzke (1958). less suited for reducing water velocity and trap- But, on the other hand, longer and higher ping sediments, replaces land cover. floods increase mortality of seedlings (Troth, If Copernicia tectorum is indeed a pioneer 1987) and juveniles, as found at our study sites, species, with discontinuous and occasional and it can also cause severe damage to adults recruitment as a result of river dynamics, the through the accumulation of debris and vegeta- expected population would consist mostly of tion that get trapped by the recurved petiole individuals belonging to just one or two size spines, and the germination of epiphytes and classes, while at other sites other size classes hemiepiphytes among the leaf bases. would be represented. This is exactly what The palm stands probably play a signifi- Troth (1967) found in the Venezuelan savan- cant role in regulating river channel dynamics nas, where no population had all size classes. in this inner delta area, where total sedimen- Troth pointed the same pattern of stands with tation has averaged 3-4 mm/yr over the past individuals of the same size and irregular rep- 7 500 years (van der Hammen, 1986; Plazas resentation of size classes in other palm species et al., 1988; Kettner, Restrepo, & Syvitski, of harsh environments. These include Washing- 2010). This rate is probably higher at the palm tonia filifera from oases in California (Vogl, & stands, as thicker plant stems and larger leaves Mchargue, 1966); from are known to be effective at capturing particles semiarid areas in Northeastern (Taube, by reducing water velocity and by providing 1952); and from hyperseason- a surface for sediment adhesion (Brueske, & al savannas in the semiarid Chaco (Puechagut, Barret, 1994; Pasternak, & Brush, 1998). As a Politi, Bellis, & Rivera, 2012). matter of fact, at one of our study sites, sedi- Population structure at all sites in Plato ment deposition at the base of some juvenile shows that only well established stands, mostly Copernicia palms reached 2cm during the with adult palms, occur at this site. In fact, at period 2010-2011. the youngest stand found (Ciénaga Cuchillo, As sediments accumulate over decades, in Plato) average height of individuals was inundation in the palm stand will decrease, 4.2m, which suggests that the last successful reducing the favorable conditions described recruitment took place ca. 30 years ago. Con- above for palm population growth. Eventually, sidering the palm’s short life span, this stand the palm grove will become non-flooded and will probably disappear within the next two seedling recruitment will decrease accordingly, or three decades. and population dynamics will reverse, lead- At the palm stands of Plato and Córdoba, ing to the eventual disappearance of the palm abundance, density and leaf production rate stand within several decades, given the palm’s offer favorable conditions for leaf harvest for short life span. As sedimentation stops, ero- handicraft manufacture. At Magangué, on the sion begins, whereas the described accretion contrary, population structure indicates a lim- process takes place in neighboring areas, where ited possibility for use, and thus leaf harvest the palm eventually starts to colonize. As in this area should be regulated, in order to accretion progresses in those areas, the former favor recovery of the palm stands. Comparison palm grove on this side would be progressively of harvested and unharvested stands at Plato invaded by water. This kind of sedimentary shows that harvest does not affect population dynamics, well documented for deltaic areas structure if only subadult and adult palms (Serodes, & Troude, 1984; Defries, 1986), are involved.

534 Rev. Biol. Trop. (Int. J. Trop. Biol. ISSN-0034-7744) Vol. 63 (2): 525-536, June 2015 Considering the role of river dynamics on RESUMEN the population fate of Copernicia tectorum, management actions must focus on reestablish- Poblaciones de Copernicia tectorum (Arecaceae) en las tierras bajas del Caribe de Colombia: una ing, as much as possible, water flow between palma pionera expuesta a la dinámica de un río. La the river and the lagoon complexes where the palma Copernicia tectorum forma grandes poblaciones en palm grows. This includes cleaning up the nat- sabanas estacionalmente inundables de la región Caribe ural channels and adjusting some infrastructure de Colombia, donde sus tallos y hojas se utilizan en cons- works in order to improve water circulation, trucción y sus cogollos para la elaboración de artesanías. Estudiamos la abundancia y la estructura poblacional en 34 as well as reverting some agricultural areas parcelas de 20×10m (0.68 ha), en tres localidades (Plato, around the wetlands to their former protective Córdoba y Magangué) en la Depresión Momposina, un function. These actions have already been iden- delta interior formado por la confluencia de cuatro grandes tified by the environmental authority (MMA, ríos. Registramos el crecimiento y la mortalidad de 164 2002) as necessary for the recovery of the wet- palmas de diferentes clases de tamaño durante 13 meses y estimamos además la mortalidad en plántulas y juveniles lands in the Mompox Depression. en dos parcelas de 10x10m en los mismos sitios. Los aná- The described actions should be combined lisis se realizaron con las pruebas de Kolgomorov-Smirnov with the implementation of any necessary (KS), Kruskal-Wallis y Mann-Whitney en Statgraphics practices involving leaf harvest itself. Under Plus and SPSS. Relacionamos la estructura y dinámica de this scenario, the appropriate management of los palmares con la intensidad de la inundación. Copernicia tectorum tiene la tasa de producción de hojas más rápida the C. tectorum stands not only offers a good registrada hasta ahora para cualquier palma (19-23 hojas opportunity for integrating use and conserva- por año en subadultos y adultos) y una vida corta de ca. 46 tion of this particular species, but may also años. La abundancia, densidad y alta tasa de producción have a tremendous impact on the decades-long de hojas de la palma ofrecen un gran potencial para el uso deltaic cycles of floodable vs. terra firme sostenible de sus cogollos (especialmente en Plato, donde hay unas 480 ha de palmares con 300-1 000 individuos/ha), areas. A better understanding of the palm’s ya que la cosecha de hojas de palmas adultas y subadultas, role in the sedimentation cycles might prob- parece no afectar la estructura de la población. La palma ably help to minimize any negative effects es una pionera de las llanuras inundables, y los palmares of river dynamics. en un sitio particular crecen y se reducen siguiendo la dinámica de sedimentación, en la cual la especie juega un papel importante. La estructura actual de las poblaciones y ACKNOWLEDGMENTS el escaso reclutamiento en las clases juveniles en el sitio de estudio sugieren que allí la población se está reduciendo. We thank Universidad Nacional de Colom- Se deben emprender acciones de manejo que apunten a bia, and the Instituto de Ciencias Naturales restablecer la dinámica fluvial natural en los complejos cenagosos en los que crece la palma. A su vez, el manejo for offering the facilities for conducting this apropiado de los palmares puede ayudar a minimizar los research. We also thank all the harvesters and efectos negativos de la dinámica fluvial. artisans of Plato and Magangué, and Nagyla Garrido and Leonardo Rivera for their sup- Palabras clave: Depresión Momposina, estructura pobla- port during field work. Financial support came cional, impacto de la cosecha, plantas pioneras, PFNM, producción de hojas, sabana estacionalmente inundable. from the PALMS FP-7 Project of the European Union (No. 212631). Support from Patrimonio Natural and USAID (Formulación de planes de REFERENCES manejo y uso sostenible de palmas promisorias Bernal, R., & Galeano, G. (Eds). (2013). Cosechar sin des- de la región Caribe que aporte a una estrategia truir: Aprovechamiento sostenible de palmas colom- de uso de recursos naturales del bosque seco bianas. Bogotá, Colombia: Universidad Nacional de tropical) was vital for writing the manuscript. Colombia.

Rev. Biol. Trop. (Int. J. Trop. Biol. ISSN-0034-7744) Vol. 63 (2): 525-536, June 2015 535 Brueske, C. C., & Barrett, G. W. (1994). Effects of vegeta- stands indifferent habitats. Folia Geobotanica, 37, tion and hydrologic load on sedimentation patterns in 225-238. experimental wetland ecosystems. Ecological Engi- Pasternak, G. B., & Brush, G. S. (1998). Sedimentation neering, 3, 429-447. cycles in a river-mouth tidal freshwater marsh. Estua- Corner, E. J. H. (1966). The natural history of palms. Lon- ries, 21, 407-415. don: Weidenfeld and Nicolson. Peters, C. (1996). The ecology and management of non- Defries, R. S. (1986). Effects of land-use history on timber forest resources. Washington, D.C.: The World sedimentation in the Potomac estuary Maryland: Bank. A water-quality study of the tidal Potomac River Pinard, M. A., & Putz, F. E. (1992). Population matrix and estuary. Washington: United States Geological models and palm resource management. Bulletin de Survey, Water-Supply Paper 2234-K, United States I’Institut Franais d’Etudes Andines, 21, 637-649. Government Printing Office. Plazas, C., Falchetti, A. M., van der Hammen, T., & Botero, Fanshawe, D. (1967). The vegetable ivory palm Hyphaene P. (1988). Cambios ambientales y desarrollo cultural ventricosa Kirk its ecology, silviculture and utiliza- en el bajo río San Jorge. Boletín del Museo del Oro, tion. Kirkia, 6,105-117. 20, 58-59. Galeano, G., & Bernal, R. (2010). Palmas de Colombia: Puechagut, P., Politi, N., Bellis, L., & Rivera, L. (2012). A Guía de Campo. Bogotá, Colombia: Editorial Univer- disappearing oasis in the semi-arid chaco: deficient sidad Nacional de Colombia. palm regeneration and establishment. Journal for Nature Conservation, 21(1), 31-36. Galeano, G., Bernal, R., Isaza, C., Navarro, J., García, N., Vallejo, M. I., & Torres, C. (2010). Evaluación de Serodes, J. B., & Troude, J. P. (1984). Sedimentation cycle la sostenibilidad del manejo de palmas. Ecología en of a freshwater tidal flat in the St. Lawrence estuary. , 45(3), 85-101. Estuaries, 7, 119-127. Henderson, A. (2002). Evolution and ecology of palms. Sokal, R. & Rohlf, F. (1995). Biometry: the principles and New York, NY: The New York Botanical Garden practice of statistics in biological research. 3rd edi- Press. tion. New York, NY: W. H. Freeman and Co. Instituto de Hidrología, Meteorología y Estudios Ambien- Taube, E. (1952). Carnauba wax - product of a Braziliam tales de Colombia. (2011). Informes hidrológicos palm. Economic Botany, 6, 379-401. diarios. Available at http://www.pronosticosyalertas. Ticktin, T. (2004). Review: the ecological implications of gov.co/jsp/loader.jsf?lServicio=Publicaciones&lTipo harvesting non-timber forest products. Journal of =publicaciones&lFuncion=loadContenidoPublicacio Applied Ecology, 41, 11-21. n&id=751 Torres, M. C. (2013). Sará (Copernicia tectorum). In R. Instituto Geográfico Agustín Codazzi. (1977). Zonas de Bernal, & G. Galeano (Eds.), Cosechar sin destruir: vida o formaciones vegetales de Colombia. Bogotá, Aprovechamiento sostenible de palmas colombianas Colombia. (pp. 190-199). Bogotá, Colombia: Editorial Universi- dad Nacional de Colombia. Kettner, A. J., Restrepo, J. D., & Syvitski, J. P. M. (2010). Spatial simulation experiment to replicate fluvial Troth, R. (1987). Ecology of woody plant communities in sediment fluxes within the Magdalena River basin, flooded savannas (Llanos) of central Venezuela, and Colombia. Journal of Geology, 118(4), 363-379. the role of Copernicia tectorum (Palmae). (Ph. D. Dissertation). University of Michigan. Kitzke, E. D. (1958). A method for germinating Copernicia van der Hammen, T. (1986). Fluctuaciones holocénicas palm seeds. Principes, 2, 5-8. del nivel de inundaciones en la cuenca del Bajo Linares, E., Galeano, G., García, N., & Figueroa, Y. (2008). Magdalena-Cauca-San Jorge (Colombia). Geología Fibras vegetales empleadas en artesanías en Colom- Norandina, 10, 11-18. bia. Bogotá, Colombia: Artesanías de Colombia S.A., Vogl, R. J., & Mchargue, L. T. (1966). Vegetation of Universidad Nacional de Colombia. California Fan Palm Oases on the San Andreas Fault. Ministerio del Medio Ambiente. (2002). Plan de Manejo Ecology, 47(4), 532-540. Integral de los Humedales, Subregión de la Depre- Wong, J., Thornber, K., & Baker, N. (2001). Evaluación de sión Momposina y Cuenca del Rio Sinú. Magangué, los recursos de productos forestales no madereros: Colombia. Experiencia y principios biométricos. (Productos Parolin, P., Oliveira, A. C., Piedade, M. T. F., Wittmann, forestales no madereros 13). Roma, Italia: Orga- F., & Junk, W. J. (2002). Pioneer trees in Amazonian nización de las Naciones Unidas para la Agricultura floodplains: Three key species form monospecific y la Alimentación (FAO).

536 Rev. Biol. Trop. (Int. J. Trop. Biol. ISSN-0034-7744) Vol. 63 (2): 525-536, June 2015